Endocarditis is an inflammation of the endocardium, the interior lining of the heart and its valves. It most often results from bacterial infection that may originate from bacteria in the blood or as a result of heart surgery. The bacteria in the blood may enter from a skin wound or even from small injuries occurring when chewing food or brushing the teeth. Injecting drug users and patients with prolonged catheter use are also at risk. Abnormal or damaged valves are more susceptible than normal ones, and people with artificial valves are at risk. Bacteria and blood clots can accumulate on the valves (called vegetation) and can then break loose and block vessels elsewhere in the body causing strokes, heart attacks pulmonary embolisms or infecting the area where they lodge.
Acute infective endocarditis has a rapid onset and can be life threatening, unlike subacute infective endocarditis which develops slowly over weeks and months. In the acute form, the symptoms are usually the sudden onset of a high fever, a fast heart rate and tiredness. There can be extensive valve damage as well as the blood clot damage elsewhere in the body. Individuals may go into shock and be subject to renal failure. Prompt diagnosis and hospitalization are vital. The subacute form is associated with mild fever, tiredness, weight loss, sweating and a low erythrocyte count. However, because the symptoms of the subacute form are more vague, damage may occur before the condition is recognized; it is just as life threatening as the acute form.
Patients with heart valve abnormalities or artificial valves are more susceptible to endocarditis, as mentioned above. If they are about to undergo medical or dental procedures, they must inform their surgeon or dentist and be given antibiotics prior to invasive treatments. If endocarditis occurs and is identified, the treatment usually consists of at least two weeks of high-dose, intravenous antibiotics. However, heart surgery may also be necessary to repair or replace damaged valves.